Figure 1

Figure 1 image is from ("Incropera, Frank. Fundamentals of Heat and Mass Transfer 6th Edition. John Wiley and Sons, 2011“)

Nucleate boiling occurs when the surface temperature is hotter than the saturated fluid temperature. During this phenomenon, many bubbles will start to form repeatedly creating many nucleic sites. This phenomenon is known as nucleation. At this regime, the heat flux (q”) and heat transfer (H) increase sharply with temperature (ΔT). The nucleation ends once the temperature of the material reaches a critical heat flux. Once the material passes the critical heat flux, it is irreversible; therefore, the goal of our experiment is to find a way for the material to maintain a high level of heat flux as the temperature increases.

We are exploring the thermal effect of epoxy to see if material selectively coated with epoxy can maintain a high heat flux.

Nucleate boiling is crucial for many engineering application. Nucleate Boiling is use for: Power generation, Electronic component cooling, Fluid handling and control.

We found that material selectively coated with epoxy forms individual heating zones creating a irregular temperature distribution over a surface. This helps the materials’ to maintain a high heat flux point and not drop as ΔT increases.

The  temperature doesn't shoot up rapidly as you do not enter in the film boiling regime.

This coating doesn't ensure the high heat flux but it shows a better performance at  high temperatures.

We conclude that material coated with epoxy can operate at much higher temperatures compares to pure material. I would like to give my greatest gratitude to all

people that contributed in the completion of this project. I would like to thank the Howard Hughes Medical Institute and Dr. Ashleigh Wright for providing me the grant and resources to complete this project. I also thank the faculty of the Mechanical Engineering Department at Louisiana State University including Dr. Shengmin Guo as my advisor, Mr. Manish Patil as my mentor, and Mr. Lance Brumfield as my technical supporter.

Material 1 Material 2 (Pure Brass) (Epoxy Coated Brass)

For our experiment we use a smaller surface area for the epoxy coated brass compares to the pure brass. Since heat flux is also proportional to surface area if we were to increase the surface area of epoxy brass we can expect a better result.

1. Machine the pin type patterns on the sample and add the epoxy layer.

2. Set up the sample in the nucleation chamber applying the thermal grease at the bottom.

3. Fill the chamber using FC-72 as a boiling medium.4. FC 72 as fluid and nucleation chamber to create boiling.5. Purge the chamber with Argon to avoid contamination.6. Set the constant heat flux value and record the temperature when

it reaches to steady state.7. Use Multilog 720 to measure temperature and heat flux. 8. Ensure that there is no leakage of FC72 during the experiment.9. Ensure that nucleation chamber is in equilibrium during the

experiment.Figure 2 image is from (https://rs2007.limsi.fr/TSF__Interface_tracking.html

(Figure 2)

Procedure

Samples

Result/Conclusion

AcknowledgementMotivation–Theory/Plan

Abstract

Nucleate Boiling Analyzing Heat Transfer on Hybrid Surfaces David Van Nguyen1, Manish Patil,2 Shengmin Guo,2*

1Baton Rouge Community College, Baton Rouge, LA 708032Department of Mechanical Engineering, Louisiana State University, Baton Rouge, LA 70803